Automatic oil spill detection system

ABSTRACT

A method for detecting and isolation a leak in a hydraulic system having a supply pump serving at least one control valve is disclosed. In one embodiment, the control valve has multiple work sections. In step of the method, the hydraulic system is activated. In another step, an actuation command for at least one of the work sections is received, for example from a human-to-machine interface. Subsequently, the method may include generating a flow demand for the work sections for which an actuation command has been received. The method also includes the step of implementing at least one of a first, second, third, and fourth leak detection and isolation protocol to detect and isolate a leak between the pump and the control valve assembly, a leak between the reservoir and the control valve assembly and a leak between the at least one work circuit and the control valve assembly.

RELATED APPLICATIONS

This application is a divisional of application Ser. No. 14/045,316,filed Oct. 3, 2013, which application claims priority to provisionalapplication Ser. No. 61/710,523, filed Oct. 5, 2012, which applicationsare incorporated herein by reference in their entirety.

BACKGROUND

Work machines, such as fork lifts, wheel loaders, track loaders,excavators, backhoes, bull dozers, and telehandlers are known. Workmachines can be used to move material, such as pallets, dirt, and/ordebris. The work machines typically include a number of work circuitsconfigured to carry out various functions of the work machine. Forexample, a work machine may have a work circuit for lifting and loweringa work implement and another work circuit for causing the work implementto rotate. The work circuits are typically powered by a hydraulic systemincluding a hydraulic pump powered by a prime mover, such as a dieselengine. It is not uncommon for such a hydraulic system to develop aleak. Where a significant loss of hydraulic fluid is lost due to a leak,a complete loss of system functions can occur. Improvements are desired.

SUMMARY

A method for detecting and isolation a leak in a hydraulic system havinga supply pump serving at least one control valve is disclosed. In oneembodiment, the control valve has multiple work sections. In step of themethod, the hydraulic system is activated. In another step, an actuationcommand for at least one of the work sections is received, for examplefrom a human-to-machine interface. Subsequently, the method may includegenerating a flow demand for the work sections for which an actuationcommand has been received. The method also includes the step ofimplementing at least one of a first, second, third, and fourth leakdetection protocol to detect and isolate a leak between the pump and thecontrol valve assembly, a leak between the reservoir and the controlvalve assembly and a leak between the at least one work circuit and thecontrol valve assembly.

The first leak detection and isolation protocol may include the steps ofmonitoring a measured pump supply pressure; comparing the measured pumpsupply pressure to a pump supply pressure lower limit; and generating ahydraulic system leak signal to close a main pump isolation valve and toset the pump to a zero flow state when the measured pump supply pressurefalls below the pump supply pressure lower limit.

The second leak detection and isolation protocol may include the stepsof monitoring a measured flow consumption at an input and an output portfor each of the hydraulic work sections; correlating the input flowconsumption to the output flow consumption to create a monitored flowconsumption correlation; comparing the monitored flow consumptioncorrelation to a flow consumption correlation limit; and generating ahydraulic system leak signal to set a zero flow demand signal to anywork section having a monitored flow consumption correlation exceedingthe flow consumption correlation limit for the work section.

The third leak detection isolation protocol may include the steps ofsetting one or more work sections to a zero flow state and recording adifferential pressure between a measured inlet and a measured outletpressure; monitoring the inlet and outlet pressure for each of the worksections and calculating a monitored differential pressure; comparingthe difference between the recorded differential pressure and themonitored differential pressure to a differential pressure change limitvalue; and generating a hydraulic system leak signal to set a zero flowdemand signal to each work section having a monitored differentialpressure that exceeds the recorded differential pressure by more thanthe change limit value. The method may also include the step of lockingout any new flow commands until the portion of the system for which aleak detection signal has been generated is reset.

The fourth leak detection isolation protocol may include, in part, thesteps of detecting a leak between the reservoir and the control valveassembly, isolating the pump from the control valve assembly, settingthe pump to a zero flow state, and generating a leak detection signal.

DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments are described with referenceto the following figures, which are not necessarily drawn to scale,wherein like reference numerals refer to like parts throughout thevarious views unless otherwise specified.

FIG. 1 is a schematic view of a first embodiment hydraulic system havingfeatures that are examples of aspects in accordance with the principlesof the present disclosure.

FIG. 2 is a schematic view of a second embodiment hydraulic systemhaving features that are examples of aspects in accordance with theprinciples of the present disclosure.

FIG. 3 is a process flow chart showing a method of operation of eitherof the hydraulic systems shown in FIGS. 1 and 2.

FIG. 4 is a process flow chart showing a first leak detection andisolation protocol for use in the process shown in FIG. 3.

FIG. 5 is a process flow chart showing a second leak detection andisolation protocol for use in the process shown in FIG. 3.

FIG. 6 is a process flow chart showing a third leak detection andisolation protocol for use in the process shown in FIG. 3.

FIG. 7 is a process flow chart showing a fourth leak detection andisolation protocol for use in the process shown in FIG. 4.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to thedrawings, wherein like reference numerals represent like parts andassemblies throughout the several views. Reference to variousembodiments does not limit the scope of the claims attached hereto.Additionally, any examples set forth in this specification are notintended to be limiting and merely set forth some of the many possibleembodiments for the appended claims.

Hydraulic System Description

Referring to FIG. 1, a hydraulic system 10 is illustrated as a schematicdiagram. Hydraulic system 10 may be part of a vehicle system, forexample, a fork lift or a telehandler. As shown, hydraulic system 10includes a pump 12 configured to provide pressurized fluid to at leastone control valve assembly 100. In the embodiment shown, pump 12 isshown as a variable displacement axial pump with a primary shut offvalve 16. However, other types of pumps may be used for pump 12, such asan over-center pump. As configured, the hydraulic pump 12 includes aninlet (i.e., a low pressure side) that receives hydraulic fluid from areservoir 14, and the hydraulic pump 12 includes an outlet (i.e., a highpressure side) that is connected to the control valve assembly 100 viasupply line 18. When the pump 12 is rotated, hydraulic fluid is drawnfrom the reservoir 14 into the inlet of the hydraulic pump 12 andexpelled from the outlet of the hydraulic pump 12 at a higher pressure.Fluid is returned from the control valve assembly 100 by a reservoirline. In the embodiment shown, the output flow of the pump 12 iscontrolled by a load-sense line 22 extending from the control valveassembly 100. Fluid is returned to the reservoir 14 via return line 20where a spring check valve 26 may be installed to maintain a nominalback pressure in the return line 20.

Still referring to FIG. 1, the control valve assembly 100 is shown asbeing a multi-section valve configured to provide selective operationalcontrol to a number of work circuits. As shown, control valve assembly100 is a two-stage control valve assembly, such as an Ultronics® ZTS16Integrated Proportional Control Valve manufactured by Eaton Corporationof Cleveland, Ohio. An example of a twin spool valve is disclosed inU.S. Pat. No. 8,239,069 to Yuan et al., filed Jun. 11, 2009, which isincorporated herein by reference in its entirety. However, it is notedthat other types of valves may be used without departing from theconcepts presented herein. In the embodiment shown, control valveassembly includes three work sections 120, 130, 140 corresponding tothree work circuits 30, 32, and 34. Although three work circuits areshown, more or fewer work circuits may be associated with control valveassembly 100. As shown, work circuit 30 includes a hydraulic motorsystem 30 a, work circuit 32 includes a double acting hydraulic actuator32 a, and work circuit 34 includes a double acting hydraulic actuator 34a. It should be understood that other types of work circuits may beoperated by control valve assembly 100.

As shown, the first work section 120 includes a first proportional valve122 and a second proportional valve 124 configured to selectivelycontrol flow to and from the work circuit 30. The position of the firstproportional valve 122 may be controlled by a first pilot valve 126while the position of the second proportional valve 124 may becontrolled by a second pilot valve 128, wherein the position of thefirst and second pilot valves 126, 128 may be controlled by anelectronic signal from a valve controller 150 or a main controller 160(discussed later). In the embodiment shown, pressure sensors 122 a, 124a are provided at the outlets of the first and second proportionalvalves 122, 124, respectively. Position sensors 122 b, 124 b, which maybe LVDT position sensors, are also shown as being provided for the firstand second proportional valves 122, 124, respectively.

As shown, the second work section 130 includes a first proportionalvalve 132 and a second proportional valve 134 configured to selectivelycontrol flow to and from the work circuit 32. The position of the firstproportional valve 132 may be controlled by a first pilot valve 136while the position of the second proportional valve 134 may becontrolled by a second pilot valve 138, wherein the position of thefirst and second pilot valves 136, 138 may be controlled by anelectronic signal from a valve controller 150 or a main controller 160(discussed later). In the embodiment shown, pressure sensors 132 a, 134a are provided at the outlets of the first and second proportionalvalves 132, 134, respectively. Position sensors 132 b, 134 b, which maybe LVDT position sensors, are also shown as being provided for the firstand second proportional valves 132, 134, respectively.

As shown, the third work section 140 includes a first proportional valve142 and a second proportional valve 144 configured to selectivelycontrol flow to and from the work circuit 34. The position of the firstproportional valve 142 may be controlled by a first pilot valve 146while the position of the second proportional valve 144 may becontrolled by a second pilot valve 148, wherein the position of thefirst and second pilot valves 146, 148 may be controlled by anelectronic signal from a valve controller 150 or a main controller 160(discussed later). In the embodiment shown, pressure sensors 142 a, 144a are provided at the outlets of the first and second proportionalvalves 142, 144, respectively. Position sensors 142 b, 144 b, which maybe LVDT position sensors, are also shown as being provided for the firstand second proportional valves 142, 144, respectively.

The control valve assembly 100 is also shown as having a valve controlsection 110. As shown, valve control section 110 is configured with aload-sense valve 112 that provides a load-sense signal to control theoutput of pump 12 via load-sense line 22 such that the pump outputmatches the flow requirements of the work circuits 30, 32, 34. Valvecontrol section 110 is also provided with a pilot pressure reducingvalve for reducing fluid pressure to an acceptable range for controllingthe position of the proportional valves 122, 124, 122, 124, 132, 134. Asupply pressure sensor 116 and a return pressure sensor 118 are alsoshown as being provided in valve control section 110.

Referring to FIG. 2, a second embodiment of a hydraulic system 10′involving a fixed displacement pump 12′ is presented. As many of theconcepts and features are similar to the first embodiment shown in FIG.1, the description for the first embodiment is hereby incorporated byreference for the second embodiment. Where like or similar features orelements are shown, the same reference numbers will be used wherepossible. The following description for the second embodiment will belimited primarily to the differences between the first and secondembodiments.

The hydraulic system 10′ is shown as having a valve control assembly100′ with a valve control section 110′. The work sections 120, 130, 140of the second embodiment are shown as being the same as the firstembodiment. However, the valve control section 110′ in the secondembodiment does not include a load-sense valve. Instead a pump speedsensor 112′ is utilized in conjunction with a bypass valve 16′, in fluidcommunication with the reservoir 14 via line 24, to control the outputflow of the pump 12′.

Electronic Control System

The hydraulic system 10 or 10′ operates in various modes depending ondemands placed on the work machine (e.g., by an operator). A controlsystem may be provided to implement the operating modes of the hydraulicsystem 10, 10′. In the embodiment shown, a valve controller 150 and amain controller 160 are shown as being in electronic communication witheach other and with the various control components in the system 10,10′. However, it should be understood that a single controller could beused to execute the operation of the hydraulic system 10, 10′ and alsounderstood that a larger number of controllers may be used. Furthermore,it should also be understood that, where multiple control valveassemblies 100 are used in a system 10, 10′ that a single maincontroller 160 may be provided in addition to a plurality of valvecontroller 150.

The electronic controllers 150, 160 are schematically shown as includinga processor 150 a, 160 a and a non-transient storage medium or memory150 b, 160 b such as RAM, flash drive or a hard drive. Memory 150 b, 160b is for storing executable code, the operating parameters, and theinput from the operator user interface while processor 150 a, 160 a isfor executing the code. The electronic controller 150, 160 typicallyincludes at least some form of memory 150 b, 160 b. Examples of memory150 b, 160 b include computer readable media. Computer readable mediaincludes any available media that can be accessed by the processor 150a, 160 a. By way of example, computer readable media include computerreadable storage media and computer readable communication media.

Computer readable storage media includes volatile and nonvolatile,removable and non-removable media implemented in any device configuredto store information such as computer readable instructions, datastructures, program modules or other data. Computer readable storagemedia includes, but is not limited to, random access memory, read onlymemory, electrically erasable programmable read only memory, flashmemory or other memory technology, compact disc read only memory,digital versatile disks or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium that can be used to store the desired informationand that can be accessed by the processor 150A.

Computer readable communication media typically embodies computerreadable instructions, data structures, program modules or other data ina modulated data signal such as a carrier wave or other transportmechanism and includes any information delivery media. The term“modulated data signal” refers to a signal that has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. By way of example, computer readable communication mediaincludes wired media such as a wired network or direct-wired connection,and wireless media such as acoustic, radio frequency, infrared, andother wireless media. Combinations of any of the above are also includedwithin the scope of computer readable media.

Electronic controller 150 is also shown as having a number of inputs andoutputs that may be used for implementing the operation of the hydraulicsystem 10, 10′. For example, controller 150 may be configured to receiveinputs from the position sensors 122 b, 124 b, 132 b, 134 b, 142 b, and144 b and inputs from the pressure sensors 122 a, 124 a, 132 a, 134 a,142 a, 144 a, 116, and 118. The electronic controller 150 may also beconfigured to receive inputs from the main controller 160, such as flowdemand signals for each of the work sections 120, 130, 140. Theelectronic controller 150 may also be configured to send outputs to avariety of components, such as the pilot control valves 126, 128, 136,138, 146, 148, the load-sense valve 112, and the main controller 160.Controller 150 may also be configured to pass any operational datathrough to the main controller 160.

Electronic controller 160 is also shown as having a number of inputs andoutputs that may be used for implementing the operation of the hydraulicsystem 10, 10′. For example, controller 160 may be configured to receiveinputs from a human-to-machine interface 166 and to send outputs to mainshut off valve 16, pump 12′, bypass valve 16′ The electronic controller150 may also be configured to receive inputs from the main controller160, such as flow demand signals for each of the work sections 120, 130,140. The electronic controller 160 may also be configured to sendoutputs to the valve controller 150 and pass operational data through tothe valve controller 150.

Method of Operation

Referring to FIGS. 3-7, a method 1000 of operating the hydraulic system10 is shown. It is noted that although FIGS. 3-7 diagrammatically showthe method steps in a particular order, the method is not necessarilyintended to be limited to being performed in the shown order. Rather atleast some of the shown steps may be performed in an overlapping manner,in a different order and/or simultaneously. Furthermore, it is notedthat any or all of the steps disclosed in relation to method 1000 may beperformed on controller 150 alone, controller 160 alone, apportionedbetween controllers 150 and 160, or apportioned among other additionalcontrollers. Furthermore, it is noted that the method 1000 may becarried out over a number of hydraulic systems simultaneously and is notlimited to being implemented only in configurations where there is a oneto one relationship between a pump and a control valve assembly.Additional controllers may be used as well.

Referring to FIG. 3, a first step 1010 is shown as activating thehydraulic system pump and opening fluid communication between the pumpand the control valve assembly. Where a main shut-off valve is providedbetween the pump and control valve assembly, this step may includeopening the main shut-off valve. Where a bypass valve is providedbetween the pump and control valve assembly, this step may includepositioning the bypass valve to direct fluid to the control valveassembly.

A second step 1012 is shown as receiving work circuit actuation commandsfrom a human-to-machine interface, such as interface 166. This interfacemay be a combination of levers associated with the various workcircuits, for example, lift, extend, side-shift, and tilt levers. In astep 1014, flow demand signals are generated to the pump and/or theindividual work sections. In one embodiment, either of the valvecontroller and main controller can proportion the flow to the worksections where the sum of the total flow demand signals exceeds thecapacity of the pump.

In a step 1016, a leak detection protocol is initiated. The leakdetection protocol may include one or more of the leak detectionprotocols 1100, 1200, 1300, 1400 outlined in FIGS. 4-7, described below.In a step 1018, the hydraulic system is deactivated until system resetif the leak detection protocol step 1016 results in the generation of aleak detection signal. Step 1018 may include deactivating the entirehydraulic system, for example by commanding the pump to a zero flowstate and isolating the pump from the control valve assembly. Step 1018may also include deactivating only a portion of the hydraulic system,for example by commanding an individual work section to a zero flowstate and isolating the associated work circuit from the rest of thehydraulic system.

Referring to FIG. 4, a first leak detection protocol 1100 is disclosed.First leak detection protocol 1100 is for detecting a leak in thehydraulic system between the pump and the control valve assembly. In astep 1110, a supply pressure lower limit is defined. In a step 1112, anactual measured pump supply pressure is monitored. In one embodiment,the pump supply pressure may be monitored at pressure sensor 116 viavalve controller 150. In a step 1114, the actual measured pump supplypressure is compared to the pump supply pressure lower limit. If themeasured value is equal to or above the lower limit, then the protocol1100 returns to step 1112 for continued monitoring. If the measuredvalue is below the lower limit, which would be indicative of a leak, forexample in line 18, the protocol 1100 proceeds to step 1116 wherein thesupply pump 12 is isolated from the control valve. Where a main shut-offvalve is provided, such as valve 16 shown in FIG. 1, step 1116 caninclude closing the valve 16 to isolate the pump 12 from the controlvalve assembly 100. Where a bypass valve is provided, such as valve 16′shown in FIG. 2, step 1116 can include moving the bypass valve 16′ to abypass state where fluid from pump 12 is directed to reservoir 14 vialine 24 and the fluid in the control valve assembly 100′ is therebyisolated from the pump 12. In the embodiment shown, the command tovalves 16, 16′ is sent by the main controller 160 which receives thepressure data from sensor 116 via controller 150. In a step 1118, thepump is set to a zero flow state while in a step 1120 any new flowcommands to the pump from controllers 150, 160 are locked out until asystem reset has occurred. In a step 1122, a leak signal is generated.It is noted that steps 1116, 1118, 1120, and 1122 may be performedsimultaneously by the controller(s) 150, 160, or in a sequentialfashion.

Referring to FIG. 5, a second leak detection protocol 1200 is disclosed.Second leak detection protocol 1200 is for detecting a leak in thehydraulic system between the control valve assembly and one or more ofthe connected work circuits when the work circuit is in use. In a step1210, a flow consumption correlation range for each work section isdefined. Because an actuator or work circuit may have inlet and outletflows that are not equal (e.g. because of different cylinder ratios andinefficiencies), a comparison between and actual correlation and ameasured correlation between the two flows can be utilized to detect aleak. Step 1210 is also shown as defining an out of range (OOR) timeperiod for establishing a minimum duration of a fault condition before aleak signal is generated. In step 1212, flow consumption for each worksection inlet and outlet port is monitored. In the embodiment shown,controller 150 monitors pressure sensors 122 a, 124 a, 132 a, 134 a, 142a, and 144 a for this purpose. In a step 1214 the measured correlationbetween associated inlet and outlet ports for each work section iscompared to the flow consumption correlation range for that worksection. Where the measured correlation is less than or equal to apredetermined correlation range or margin, the protocol 1200 returns tostep 1212. Where the measured correlation is more than the predeterminedcorrelation range or margin, which would be indicative of a leak in thework circuit, the protocol 1200 proceeds to step 1218. In step 1218, theout of range work section is set to a zero flow condition and locked outfrom receiving any new flow commands until system reset while step 1120includes the generation of a leak detection signal. Unlike leakdetection protocol 1100, protocol 1200 allows the hydraulic system to atleast be partially operative by isolating only those work sections forwhich a leak is detected. Accordingly, protocol 1200 will continuallymonitor all active work sections even if a leak signal has beengenerated for one or more of the other work sections. It is noted thatsteps 1216, 1218, and 1220 may be performed simultaneously by thecontroller(s) 150, 160, or in a sequential fashion.

Referring to FIG. 6, a third leak detection protocol 1300 is disclosed.The third leak detection protocol 1300 is for detecting a leak in thehydraulic system between the control valve assembly and one or more ofthe connected work circuits when the work circuit is in a zero flowstate. In a step 1310, a zero flow state differential pressure changelimit is defined, as is an out of range time period. In a step 1312, awork section is closed to achieve a zero flow state. In a step 1314,port pressures at each closed work section are recorded and adifferential pressure between the inlet and outlet of each work sectionis calculated. In the embodiment shown, controller 150 monitors pressuresensors 122 a, 124 a, 132 a, 134 a, 142 a, and 144 a for this purpose.In a step 1316, the differential pressure between each inlet and outletport for each work section is monitored. Where the difference betweenthe monitored and recorded differential pressures is less than or equalto the change limit, the protocol returns to step 1316 for continuedmonitoring. Where the difference between the monitored and recordeddifferential pressures is equal to or greater than the change limit forthe out of range time period, the protocol proceeds to step 1320. Atstep 1320, the out of range work section is set to a zero flow conditionand locked out from receiving any new flow commands until system resetwhile step 1322 includes the generation of a leak detection signal.Similar to leak detection protocol 1200, protocol 1300 allows thehydraulic system to at least be partially operative by isolating onlythose work sections for which a leak is detected. Accordingly, protocol1300 will continually monitor all active work sections even if a leaksignal has been generated for one or more of the other work sections. Itis noted that steps 1320 and 1322 may be performed simultaneously by thecontroller(s) 150, 160, or in a sequential fashion.

Referring to FIG. 7, a fourth leak detection protocol 1400 is shown.Fourth leak detection protocol 1400 is for detecting a leak in thereservoir line between the control valve assembly and the reservoir. Ina step 1410 of protocol 1400 a flow consumption correlation range andminimum pressure range for the reservoir line are defined, as is an outof range time period. In a step 1412, the reservoir line pressure rangeis monitored when there is a flow command or a zero flow state. As thecheck valve 26 provides a back pressure to the reservoir line, a minimumpressure in the line, for example at pressure sensor 118, would normallybe anticipated. Where the pressure falls below the nominal back pressurerequired by the check valve 26, a leak can be expected to have occurred.Additionally, during a flow state, the correlation between the supplyflow and the return flow can be monitored against a calculatedcorrelation range to ensure that a leak also has not occurred. Thesecomparisons are shown at step 1414, where the protocol 1400 returns tostep 1412 for continued monitoring if the measured state is within thecorrelation range and above the minimum pressure range. Where themonitored and measured values are outside of the set ranges for the outof range time period, a leak in the reservoir line is detected and thepump is isolated from the control valve assembly at a step 1416 in amanner similar to that described for step 1116 the first leak detectionprotocol 1100. In a step 1418, the pump is set to a zero flow statewhile in a step 1420 any new flow commands to the pump from controllers150, 160 are locked out until a system reset has occurred. In a step1422, a leak signal is generated. It is noted that steps 1416, 1418,1420, and 1422 may be performed simultaneously by the controller(s) 150,160, or in a sequential fashion.

Where a hydraulic system is configured to implement all four of the leakdetection protocols 1100 to 1400, the system can be protected from aleak in the main supply line between the pump and the control valveassembly, from a leak in the reservoir return line between the reservoirand the control valve assembly, and from a leak in any of the individualwork circuits regardless of whether the work circuits are being used ornot. Furthermore, the system can be configured to isolate the leak inthe system once detected in a very small amount of time, for example afew milliseconds, thus minimizing any oil spill. Additionally, thecontroller 150 and/or 160 can be configured to take into accountdifferences in cylinder ratios and inefficiencies in the actuators suchthat the leak detection protocols are optimized. Accordingly, thedisclosed system will operate to significantly limit the volume ofleaked hydraulic fluid should a leak in the system occur.

The various embodiments described above are provided by way ofillustration only and should not be construed to limit the claimsattached hereto. Those skilled in the art will readily recognize variousmodifications and changes that may be made without following the exampleembodiments and applications illustrated and described herein, andwithout departing from the true spirit and scope of the disclosure.

What is claimed is:
 1. A hydraulic system comprising: (a) a controlvalve assembly having a main inlet port and a main outlet port andhaving at least one work section in fluid communication with at leastone work circuit; (b) a pump in fluid communication with the main inletport of the control valve assembly; (c) a reservoir in fluidcommunication with the main outlet port of the control valve assembly;and (d) an electronic controller configured to detect a leak between thepump and the control valve assembly, a leak between the reservoir andthe control valve assembly and a leak between the at least one workcircuit and the control valve assembly; (e) wherein the electroniccontroller is configured to implement a first leak detection protocol toisolate the pump from the control valve assembly upon the detection of aleak between the pump and the control valve assembly; (f) wherein theelectronic controller is configured to implement a second leak detectionprotocol to isolate the reservoir from the control valve assembly uponthe detection of a leak between the reservoir and the control valveassembly; (g) wherein the electronic controller is configured to isolatethe at least one work circuit from the control valve assembly worksection upon the detection of a leak between the work circuit and thework section.
 2. The hydraulic system of claim 1, wherein the electroniccontroller is configured to implement a third leak detection protocol todetect and isolate a leak between the work circuit and the work sectionwhen the work section is in a flow state.
 3. The hydraulic system ofclaim 2, wherein the electronic controller is configured to implement afourth leak detection protocol to detect and isolate a leak between thework circuit and the work section when the work section is in a zeroflow state.
 4. A hydraulic system comprising: (a) a control valveassembly having a main inlet port and a main outlet port and having atleast one work section in fluid communication with at least one workcircuit; (b) a pump in fluid communication with the main inlet port ofthe control valve assembly; (c) a reservoir in fluid communication withthe main outlet port of the control valve assembly; and (d) anelectronic controller configured to detect a leak between the pump andthe control valve assembly, a leak between the reservoir and the controlvalve assembly and a leak between the at least one work circuit and thecontrol valve assembly; (e) wherein the electronic controller implementsall three of a first, second and third leak detection and isolationprotocol, wherein: i. the first leak detection protocol is implementedto isolate the pump from the control valve assembly upon the detectionof a leak between the pump and the control valve assembly; ii. thesecond leak detection protocol is implemented to isolate the reservoirfrom the control valve assembly upon the detection of a leak between thereservoir and the control valve assembly based on a first flowconsumption correlation range; and iii. the third leak detectionprotocol is implemented to detect and isolate a leak between the workcircuit and the work section based on a second flow consumptioncorrelation range when the work section is in a flow state.
 5. Thehydraulic system of claim 4, wherein the electronic controller isconfigured to implement a fourth leak detection protocol to detect andisolate a leak between the work circuit and the work section when thework section is in a zero flow state.